It can be a muscle pull. But it can also be a disc bulge problem which generally causes compression of nerve and pain travels sown the hip and thigh+increases with sneeze /cough.
Next Steps
Go to a physiotherapist.. Ultrasonic therapy +IFT +Heating therapy +some strengthening exercises will be helpful for sure.
Health Tips
At home.. Rest +hot water fomentation +pain killer gel +no long sitting /standing /travelling /driving /walking +no stair climbing +no cold exposure +no manual exertions +no weight lifting +use lumbo sacral belt.